What type of threat is presented when a staff member installs a remote-access Trojan on a server?

A remote-access Trojan (RAT) is a type of malware that allows unauthorized access and control over a computer or server, typically without the user's knowledge. When a staff member intentionally installs such a malicious software on a server, it is considered an insider threat. This designation stems from the fact that the threat arises from someone within the organization, who has authorized access to the system and misuses that privilege for malicious purposes.

Insider threats can be particularly challenging to manage and mitigate because they often exploit legitimate access to systems and data. In this scenario, the insider (the staff member) leverages their trusted position to introduce a security risk, which can lead to significant consequences, such as data theft, system compromise, or further propagation of malware within the organization's network.

Identifying this as an insider threat highlights the importance of monitoring employee behavior, implementing separation of duties, and establishing strong access controls to minimize the risk posed by individuals who have legitimate access to sensitive systems and data.